1. Field of the Invention
The present disclosure relates to a mobile terminal device having an input section with a touch input region superimposed on a display screen and to an input device provided for such a mobile terminal device.
2. Description of the Related Art
Heretofore, mobile phone terminals have been designed to input characters as well as numerals by assigning characters to numeric keys, or hardware keys, respectively. In this case, two or more characters are assigned to the same key so that a desired character can be input as a result of selecting the corresponding key by switching character types and pushing the key predetermined times. However, this procedure may lead to complicated and time-consuming operation because of an increase in average number of times of pushing the key until it reaches the character of interest.
For improving such a procedure, there is proposed a technology for inputting a desired character by displaying a representative image of character classification on a display screen, operating a rotary input section to specify a desired class to display a list of characters belonging to the class, and then operating the rotary input section again to select the desired character from the list (see, Japanese Unexamined Patent Application Publication No. 2003-256117).
Furthermore, there is also proposed a software keyboard for personal digital assistant, where an input region is defined on a display screen to display a full keyboard. The software keyboard includes keys that allow the user to input a desired character by pointing an input pen at the corresponding key (see, Japanese Unexamined Patent Application Publication No. 2000-322181, which will be also referred to as JP 2000-322181 A).
In recent years, there is also proposed a technology for allowing the user to point a desired character from characters displayed on the display screen on a touch panel using the user's own finger without using an input pen (see, Japanese Unexamined Patent Application Publication No. 2009-288873, which will be also referred to as JP 2009-288873 A).